The advantage that symmetric algorithms for encryption have over the asymmetric algorithms is that processing and encryption in symmetric key algorithms is very fast as compared to asymmetric encryption. The symmetric algorithms are less intensive in terms of their computation as a result they can be processed faster. As a result the symmetric encryption method is used for the encryption of sessions. The high speed of the symmetric encryption is suitable for bulk processing of encryption. As mentioned earlier, there are many forms of symmetric algorithms of which DES and DEA are the most popular and widely used.
“DES uses 64-bit blocks with a 64-bit key (although only 56 bits are significant; the other 8 are parity bits). The bits within a block are shuffled and XOR’ed with the key in a sequence of 16 substitutions called “rounds”, to create the ciphertext. Applying the same process (with the same key) to the ciphertext restores the original plaintext, so the process is symmetric. It has been very widely used, by the US government and commercial organizations around the world, including many financial institutions. It is easy to code (and there are good public domain implementations) and as it only involves bit-shifting operations combined with a few small look-up tables it doesn’t impose too much of a computational load.” (Crampton, 2004)
DES is a form of symmetric algorithm which uses simple bit shifting. With super computers it is now possible to crack the DES encryption, and with the way technology is progressing, in the future even desktops can be used to crack DES making the symmetric encryption form a not very safe and secure option for encryption.